Mr Murphy, who represented himself in the judicial review challenge, is now considering whether to appeal the verdict.

The ornithologist took legal action in an attempt to halt construction of the part of the road near Moosbawn, Co Derry - the childhood home of the former Nobel laureate poet.

The route was identified following a public inquiry nearly a decade ago.

With commuters regularly facing rush-hour gridlock, former Infrastructure Minister Chris Hazzard gave the green light to the scheme last year in a bid to significantly improve a major transport corridor.

Proceedings centred on ecological checks made to potential disturbance to whooper swans on Lough Neagh and Lough Beg from the disputed Toome to Castledawson stretch.

Mr Murphy claimed the plans will cause irreparable harm to an area worthy of word heritage status.